This disclosure generally relates to systems and methods for viewing speed profile, and controlling the speed of an aircraft, and more particularly relates to systems and methods for enabling a pilot to manually intervene in order to depart from a preprogrammed speed profile.
Modern commercial aircraft are equipped with several aircraft systems to manage their flight profile and configuration. For example, one of the several functions of the flight management computers (FMC) entails the planning and management of the flight plan of an aircraft from takeoff to landing. The mode control panel provides means for pilots to manage certain aspects, such as controlling to the lateral and vertical flight profiles of an aircraft, or managing the airplane tactically. Both the FMC and mode control panel may be used to control the autopilot and autothrottle systems, which may in turn send commands to other aircraft systems such as the engines and flight control systems to direct and control the aircraft consistent with the pilots' commands. Feedback as to the performance of the aircraft in relation to the pilots' commands may be available in a number of locations in the cockpit (flight deck) including the primary flight displays, navigation displays, engine displays, mode control panels, control display units, and crew alerting displays.
As aircraft and the airspace environment in which they operate have evolved to become more complex, aircraft systems available to pilots, as well as the flight profiles pilots manage, have become more complex. One aspect of a flight profile whose management poses a challenge is understanding and managing the entire speed profile. The speed profile of modern commercial aircraft is influenced by myriad inputs. For example, such input may include the aircraft's speed capability and optimum economic performance given certain input constraints, such as the aircraft's configuration, available weather data, ATC tactical speed requests for spacing etc., and desired time of arrival control. The speed profile may also be influenced by altitude-based restrictions, such as speed at-or-less than 250 knots below 10,000 feet. Furthermore, an aircraft's speed may also be constrained by speed restrictions or constraints attached to waypoints that define the aircraft's route. In addition, performance requirements related to new air traffic management (ATM) functions such as continuous descent approaches may also have to be factored in to obtain a more comprehensive assessment of the speed profile for an aircraft.
The combination of these various types of influences on the aircraft's speed, which are managed with safety and fuel economy objectives as well, can result in a complicated speed schedule that can be difficult to comprehend utilizing the aforementioned multiple systems currently engaged in speed profile management. The need to understand, monitor and utilize these different systems contributes to increased workload, and potentially to errors or anomalies. Thus a tool that simplifies the flight crew's awareness and management of the aircraft speed profile in all phases of flight would be advantageous.